Vahtras O. Integral approximations for LCAO-SCF calculations / O.Vahtras,J.Almlof,M.W.Feyereisen, 1993. - 12 p. - Текст : непосредственный.
Ab initio calculations of X-ray emission from C60 / J.-H.Guo,Y.Luo,O.Vahtras и др., 1994. - 12 p. - Текст : непосредственный.
Direct,atomic orbital,static exchange calculations of photoabsorption spectra of large molecules and clusters / H.Agren,V.Carravetta,O.Vahtras,L.G.M.Pettersson, 1994. - 14 p. - Текст : непосредственный.